Metal container and the like



A. B. A. FICH.

METAL CONTAINER AND THE LIKE.

- APPLICAHON FILED SEPT. 20, 1920.

1,227,152. 2 Patented Aug. 29, 1922.

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unites ALFRED BERTHOLD ANDREAS FIGHT, OF COPENHAGEN, DENMARK.

Specification of Letters Patent.

Patented Au 29,1922.

Application filed September 20, 1920. Serial No. 411,490.

To all whom it may concern:

Be it known that I, ALFRED BERTHOLD ANDREAS F1011, subject of the Kingof Denmark, residing at Islands Brygge 11, Copenhagen, Denmark, haveinvented new and useful Improvements Relating to Metal Containers andthe like, of which the following is a specification.

As it is well known, it is common to open tin cans for preserved goodsand the like by tearing open the cover of the can, or the can itself,either with or without the use of a special key, and the tearing isrendered possible by reason of the material of the can being weakened incertain lines along which the tearing is intended to be effected.

It is well known, however,that tear fre quently fails to follow theweakened lines but will diverge therefrom before the operation isfinished in satisfactory manner. When such improper tearing results, itis frequently necessary to mutilate the contents of the same in removingit.

According to the present invention, the

weakening of the said lines in tin covers is effectedby rendering thematerial brittle along the said lines. And further, according to thisinvention the material is compressed instead of being scratched or cutdown in thickness as heretofore. By this compression, which is one ofthe distinguishing features, of the present invention, the materialwhich is usually soft becomes brittle, as above stated, and experiencehas shown that if the material is reduced to a suitable minimumthickness, for instance 0.06 to 0.1 millimeter, then the tin cans whosematerial is weakened in this manner will be exceedingly easy to open, asthe percentage of error, that is to say the number of cans in which theprocess of opening fails, is less than one per cent of the total numberof cans. The principal reason for this .is that the weakening producedby the compression is extremely uniform, and that. it is very mucheasier to produce a uniform thickness of metal all along the weakenedlines by the said compression than by means of scratching or cuttingtools, which practically all make an incision of definite depth in thematerial. Differences in the thickness and hardness of the materialconse-,

actly similar to the lines to be weakened, is blunt. I

The drawing represents one embodimen of the invention,

Fig. 1 showing the upper die and Fig. 2 the lower die in a press adaptedto perform the. above mentioned operation, while Fig. 3 shows the bottomdie in top view,

and Figs. 4: and 5, respectively, show a to view and a longitudinalsection of a modified -construction of the die with a steel stripinserted.

The upper die consists of a hardened stopping die member 1 which isshaped as a ring and encircles a'plate 2 which is held, in suitableknown manner, in the die holder 3. The die plate 2 supports a form plate4: whose lower face is shaped according to the cover or the like whichis to be treated in the press, so that during the pressing operation thecover is contained in a space between this plate 1 and a correspondingplate 5 in the bottom die. The said plate 5 is encircled by a ring 6which is So much larger than the plate 5 that a narrow slot is formedbetween the latter-and the said ring, so that a hardened steel strip 7may According to the invention this steel edge, whose shape isex-' bedriven down into this slot and held in I position there. The height ofthe ring 6 is such that the steel strip 7 projects slightly, forinstance 0.25 to 0.3 millimeter beyond the'top surface of the ring, andthe ring 1 in the top die is'of such height that when the top die ismoved down towards the bottom die, the motion of the top die will bestopped by the said ring 1 meeting a fixed stop 8 on the bottom die, sothat there will be left, between the blunt top edge of the steel strip 7and the working surface 9 of the die plate 2 in the top die, a verysmall space equalling the thickness of metal in the weakened grooves inthe treated .tinplate. The rings 1 and 6, the die plate 2 and the steelstrip 7 must be ground in such a manner that the opposite faces on therings 1 and 6, respectively, and on :the

strip 7 and the die plate 2 are perfectly fiat and parallel. treated isplaced on the disc 5 in such a mannerthat-it covers the steel-strip 7whose shape .correspondsexactly to the shape of the lines which are tobe weakened inthe tinplate.

The top die .is now moved down towards .thebottom die and, as mentionedabove, the latter will be stopped in such a position that-there will .beleft, between the top surface .of. the strip 7 and the bottom 'face 9ofthe plate 2 adefinitely-determined slight space which determines thethickness of metal in the lines weakenedthereby in the tinplate.

it is not necessary to take any kind of precautions in order to avoidthe possibility of .unevennesswin the weakening of the c ov ers. Thepress works with absolute accuracy, without regard to the thickness ofthe material used, and the lifeof one single steel strip is exceedinglylong,-so that one single steel strip may be used for several yearsduring continuous operation of the 'whichisexceedingly slight incomparison with the costs heretofore incurred in repaarmg'presses of'thepresent kmd, when the working tools have been damaged.

If-it be desired to increase the weakeninsomezpaperor metal .foil, of athickness cori responding 'to the increase of the compression, must "beinserted between the die plate 2 andEthe: pressing head or die holder 3and, if itu-be desired to reduce the depth of the weakening, ::paper ormetal foil of a thick nesscorresponding to the decrease must be insertedbetween the ring l and the press ingihead The tinplate or'cover to beThe only member I The die into which the strip 7 is inserted mayobviously also be used as the top die instead of as the'bottom die.

In the construction shown in Figs. 4 and 5., the steel strip 7ends-blindly at both ends, the strip being inserted into and pass .ingback and forth through two essentially parallel slots converging at oneend in such a manner that when for instance a tinplate cover is beingweakened, there Will'be impressed therein two mainly parallel weakenedlines convergin at one end.

Having now particularly described and ascertained the nature of my Sitldinvention and in what manner the same is to be per-f formed, I declarethat what I-claim is 2- l. An apparatus for producing weakened lines inmetal tin plate comprising a die;-

a-nd an edgewise disposed steel strip inserted 1n said die, saidstrip=hav1ng aworlnngiedge rectangular throughout and projecting beyondthe pressing face of said die, said rectangularworking edge beingentirely ffree from any adjacent members so as to insure thatthe'entireedge will act upon the me'ta'l plate worked upon and willexert a -compressing action,as distinguished from a dis placingaction,along the lines to be Weak ened in said plate.

'2. An apparatus for producing weakened lines in metal plates comprisinga diefsaid 'ul'ar' die" strip having a working edge recta n throughoutand projecting beyond "said and entirely free from any adjacent m'embersa hardened I steel member engaging the rear edge of said steel str'ipyaringyencircling the steel strip andsecuring the latter to the hardenedsteel member; and a plate encircling said ring, there being between"sald ring andsaidxplate a 'narrow slotto *receive the steel strip.

Zip-An apparatus for producingweake ned lines in' metal platescomprising a'die, said strip having a working edge rectangularthroughout and projecting beyond said die and entirely free from anyadjacent mem-{ bers; a hardened steel mem 'ber engaging the rear edge of:said steel :strip; a ring encircling the steel strip and securing thelatter to the hardened steel member; and a plate encircling :said ring,there :being between said ring and said plate a 11arr0W" SlOt -t0receivetlie steel strip, saidpla'tehaving a perforation in order-tofacilitateahe separation of the ring and the plate.

a. An apparatus for forming closures --for metal "containers comprisinga die and a companion die member means tolimi't :the movement of saiddie and die member td ward each other so that the majorj-portions of thedie and'die member will not compress the metal worked upon; and portionsI on said die and die member b etween wlrich fflthe metal worked npon isadapted to be compressed by the relative movement bemy name in thepresence of two subscribtween the die and mfimber, saiddportions ingwitnesses. comprisin a fiat wor in face a a ted to compress %he metalwith ut displacihg the ALFRED BERTHOLD ANDREAS 5 same in a directionperpendicular to the WVitnesses:

direction of the compressing force. HENRIK WOLFE,

In witness whereof I have hereunto signed CARL HEMMINGSEN.

